Powerful tech industry groups have asked the U.S. Senate to drop a plan to require Internet companies to report terrorist activity on their platforms, as the provision could potentially raise privacy issues for users.

Section 603 of the Intelligence Authorization Act for Fiscal Year 2016 would require Internet services companies, who obtain ”actual knowledge of any terrorist activity,” to provide to the appropriate authorities the “facts or circumstances” of the alleged activities.

Describing “any terrorist activity” as a vague and overbroad term, the Internet Association, Reform Government Surveillance and Internet Infrastructure Coalition have in a letter Wednesday warned that the provision could result in “overbroad reporting to the government, swamping law enforcement with useless information, and potentially raising First Amendment and privacy concerns for the user who posted the item.”

“The core term that triggers the reporting mandate, any ‘terrorist activity,’ is infeasible due to its breadth,” wrote the organizations that are backed by large tech companies like Microsoft, Facebook, Apple and Google. “It is not a legal term of art nor is it ever defined in the legislative text.”

The proposed reporting obligation will also be different from current mandatory reporting requirements for child sexual abuse imagery under U.S. law, as the content in child pornography is in itself unlawful, usually easy to detect, and is not protected speech under the constitution, according to the letter addressed to Senate Majority Leader Mitch McConnell and Minority Leader Harry Reid. A key senator had earlier compared the provision on terrorist activity to existing provisions on reporting child pornography.

Over 30 civil rights groups and trade bodies also wrote to key senators earlier this week, warning that section 603 would create incentives for Internet services providers to over-report on the activity and communications of their users, just to avoid violating the law.

The facts and circumstances associated with alleged terrorist activities would in some cases include the contents of private communications, such as emails, private messages on social media, files and photos stored on cloud services, “which law enforcement would ordinarily be required to obtain a warrant to access,” the groups wrote in a letter on Tuesday.

The provision has faced opposition in the Senate as well. Senator Ron Wyden, a Democrat from Oregon, put a hold last week on the bill, saying that he wanted to work with colleagues to revise or remove Section 603 so that the rest of the bill could move forward. The House of Representatives passed a version of the Intelligence Authorization Act in June.